Transduction with HIV vectors of peripheral blood B cells activated by T cells and cytokines.

(A) Purified B cells were cultured with irradiated EL-4 T cells in the presence of IL-1β, TNF-α, IL-2, and IL-10 (see “Materials and methods”). At different times of this primary culture, the B cells were isolated and cultured in fresh medium/cytokines with HIV vectors expressing GFP under the control of the CMV, CAG, or EF1-α promoters (MOI, 10). After 15 hours, fresh irradiated EL-4 cells were again added (secondary culture). Shown are percentages of GFP⁺ cells among gated CD19⁺ 7-AAD^low (nonapoptotic) cells detected after 4 days of secondary culture. Data are from 14 independent experiments in which transductions on 3 or more different days were compared; numbers of data for different days are indicated (n). The columns show means, and the bars indicate ± 1 SD. (B) Transduction was vector-dose dependent. B cells activated for 4 days in primary culture were transduced and then cultured and analyzed as above by using HIV-GFP vectors with the compound CAG or the CMV promoter in the same experiment; MOI is indicated in the figures. Shown are FACS histograms for GFP⁺ cells by gating on CD19⁺7-AAD^low cells.